Ames Research Center, Moffett Field, California
The Pegasus software is used as a pre-processor for overset-grid computational fluid dynamic (CFD) simulations. The main features of the software include: automated hole cutting algorithms; a projection scheme for fixing small discretization errors in overset surfaces; efficient interpolation search methods; hole-size optimization based on adding additional layers of fringe points; and an automatic restart capability. The code can be run in parallel using the Message-Passing Interface standard. The parallelization performance provides efficient speed-up of the execution time capable of utilizing dozens or even hundreds of processors.

Langley Research Center, Hampton, Virginia
The NASA Langley Aeronautics Systems Analysis Branch (ASAB) is heavily involved in research studies to evaluate new and emerging concepts targeted at improving the National Airspace System (NAS). The primary tool used by ASAB to perform these studies is the Airspace Concept Evaluation System (ACES), a medium-fidelity, NAS-wide simulation environment.

NASA’s Jet Propulsion Laboratory, Pasadena, California
The current flight software approach is monolithic in nature. Every module has tentacles that reach deep within dozens of other software modules. Because of these interdependencies between modules, functionality is difficult to extract and reuse for other missions.

Ames Research Center, Moffett Field, California
This software conducts preliminary design studies for spacecraft missions. It supports a collaborative work environment that allows multiple engineers to work simultaneously on the same design. When designing a spacecraft or mission, it is important that each engineer has concurrent data information to ensure consistency in the overall design. However, the complex nature of different subsystems poses a unique problem, because certain inputs require outputs from different subsystems, and all data must be current in order to reach a systematic solution. With ATLAS, when a design is adjusted based on analysis results, new design parameters can be seen by all other clients. Various existing commercial software tools perform similar functions, but none are known to be specifically tailored toward collaborative design of spacecraft missions. ATLAS provides analysis tools with a shared data environment supporting shared work.

John F. Kennedy Space Center, Florida
In the context of systems health management, simulations serve many uses. For one, the underlying physical models can be used by model-based health management tools to develop diagnostic and prognostic models. These simulations should incorporate both nominal and faulty behavior with the ability to inject various faults into the system. Such simulations can therefore be used for operator training, as well as for developing and prototyping health management algorithms.

Goddard Space Flight Center, Greenbelt, Maryland
Scientists need to be able to quickly develop and run parallel simulations without writing low-level message passing codes using compiled languages such as C/C++/Fortran. Traditionally, high-level languages that support rapid development, such as MATLAB, IDL, Mathematica, and Python, have not addressed parallel computing needs. Other parallel tools for high-level languages are very early in the development process and not mature, are very expensive and not open source, are typically limited to one or two models of parallel computing, do not allow collaborative parallel computing, have not fully addressed error handling, and are not asynchronous in nature.

Lyndon B. Johnson Space Center, Houston, Texas
AMBER is an automated tool for performing transient loads analysis of structural systems composed of one or more flexible bodies. Each body is initially supplied in Craig-Bampton form. Two basic solution approaches are available: traditional system assembly and multibody. The traditional approach is better suited for linear systems or for comparison to legacy analysis; the multibody approach is better suited for systems having gap or friction nonlinearities at the body-to-body interfaces, or for non-traditional damping.

Question of the Week

This week's Question: This month, the Federal Aviation Administration proposed long-awaited rules on the commercial use of small drones, requiring operators to be certified, fly only during daylight, and keep their aircraft in sight. The ruling,...